Project Paper
Octobot: Tortoise-Inspired Soft Robot for Locomotion and Grasping
Soft Robotics | Mechanical Fabrication | Pneumatic Actuation | Design Iteration
Octobot is a four-legged, pneumatically actuated soft robot designed for terrain-adaptive locomotion and object manipulation. Inspired by tortoise locomotion, the robot integrates fiber-reinforced actuators and a granular jamming gripper to enable omnidirectional movement and stable grasping. Our team’s design was awarded Best Locomotion in a competitive soft robotics showcase.
I led ideation, mechanical fabrication, prototyping + testing jigs and gait development, contributing extensively to system refinement.
Contributions
Mechanical Design & Testing Infrastructure:
• Initiated design exploration, leading to our biomimetic 'turtle-bot' concept
• Developed multiple testing jigs to evaluate leg angles across 1D–3D rotation spaces
• Introduced a snap-fit octagonal rig to allow standardized, reconfigurable leg placement for repeatable testing
• Diagnosed and resolved issues with mold deformation and leg fatigue under pneumatic cycling
Actuator Development:
• Evaluated and rejected PneuNets in favor of custom fiber-reinforced actuators using Kevlar + muslin wraps
• Experimented with silicone types and curing conditions (Dragon Skin 10/30, Ecoflex, vacuum oven vs. overnight cure)
• Tuned fiber wrapping patterns to allow directionally biased motion while avoiding silicone extrusion ("bubbling")
Body Prototyping & Material Optimization:
• Iterated from PLA to flexible TPU 3D prints to reduce body weight and improve compliance
• Designed isotropic bottom skins to guide motion through friction anisotropy
Gait Development:
• Designed and tested gait sequences using programmable pneumatic systems with pressure regulation
• Developed an effective locomotion strategy using friction differentiation—modulating leg-end textures to create unidirectional push
Gripper Integration:
• Integrated a rice-filled granular jamming gripper at the body center for stable grasping without shifting center of mass